Quite interesting. Looks like with this one can do many test themselves without going to healhcare faclities. One day I was walking under sun and felt dizy thought if I can make my own blood pressure mnitoring device.

@Garcia - this would only be a hobby project so no certification necessary,

For the electrodes, the PE project used copper or brass disks, covered in lint which they recommend soaking in salt water for conductivity, applied to skin cleaned with shampoo or surgical spirit. I tried to post a pic but cannot get it to work. I read somewhere else that nickel-silver coins, with a socket or clip soldered on, are also good electrodes.

@David: "I think ECG and muscle activity signals are of similar amplitudes to brain waves, and pickup techniques are similar"

Yes, you are completly right. About five years ago, a doctor that worked in a local hospital called me in order to evaluate the possibility of creating a start-up company.

He worked on EMG for healing muscular injuries and the signal amplitudes and frequencies were so easy to deal with -- tens of milivolts and KHz range. But the point was that the medical certified cables and sensors were extremely expensive!!

In this way, I think this project is very interesting -- the problem is certification if you want to use it in professional medical products.

By the way... the conductive gel is used in the next way.

Apply it over the skin in order to increase conductivity.

Then, you need to scratch the most external skin layer -- but you don't need a flesh wound!!

Finally, attach a conductive sensor over the wet scratched skin

And you are ready to work!!

I must confess that I did some simple tests by just attaching an oscilloscope to my arm in different points :-)

@Garcia...thanks for that....the PE one just used 741s (well this was in 1973!). If I built it I'd use IAs or at least higher spec opamps, but sounds like the Bitalino could do this sort of stuff quite easily (I think ECG and muscle activity signals are of similar amplitudes to brain waves, and pickup techniques are similar)?

Interesting goodie. Years ago Practical Electronics offered a couple of articles on a "Biofeedback" monitor which used feedback form your brain waves to help you relax (among other things). I have the articles but not the time to build the damn thing. This does not seem to offer any EEG (brain wave) monitoring directly, but I might read more and see if it can do that. (sigh - there's so much interesting stuff around....)